This invention relates to the field of data recording and playback. More particularly, it relates to disk handling systems and apparatus for loading data storage disks onto a spindle assembly for rotation relative to a write/read head.
The desirability of handling high density data storage disks, e.g. optical and hard magnetic disks, without contacting their delicate data recording surfaces is manifest. With this in mind, it is known in the art to mount such disks in rigid frames, sometimes known as disk "carriers," which serve to support such disks only at their peripheries. Loading of a disk onto the drive spindle of a disk drive unit is effected by apparatus which contacts and manipulates only the disk carrier structure. See, for example, the disk handling system disclosed in U.S. Pat. No. 4,481,617 to Mabry.
In disk handling systems of the above type, the disk carrier component comprises a generally rectangular planar frame having a central circular opening for receiving a disk. The disk is captured within such opening by a plurality of radially extending tabs which extend slightly into the circular opening, on both sides of the disk. By design, the spacing between such disk-capturing tabs is somewhat greater than the disk thickness, thereby enabling the disk to be rotatably driven within the carrier frame, without physically contacting such frame. When loaded into the disk drive unit, the disk carrier must be precisely located relative to the drive spindle so that, when it's captured disk is seated on the drive spindle, the carrier itself is sufficiently spaced from the disk as not to interfere with the disk's rotation.
To alleviate the problem of having to precisely locate a disk carrier so that its captured disk can be rotated within it without interference, one may merely increase the spacing between the disk and the carrier's disk-capturing features. While a relatively "loose fit" between disk and carrier may be an acceptable solution when dealing with data storage disks of a relative rugged nature, it becomes an increasingly unacceptable solution with increasing disk fragility. In fact, certain types of data storage disk can be easily damaged by the axial and lateral movements allowed by disk carriers of the above type. Ideally, such disks should be securely retained within the carrier during all periods of non-use and, just prior to periods of use, released from the carrier and transported to a desired plane of rotation, spaced so far from the carrier that there is no potential for disk/carrier contact during disk rotation. To date, a disk handling system capable of implementing this ideal has not been devised.